Tag: stars

The life of a star, in 14 minutes

By Phil Plait | September 27, 2012 10:55 am

A popular style of do-it-yourself video is what I think of as the "stop-motion whiteboard drawing", where someone films someone else drawing on a whiteboard, explaining some concept or another. It’s surprisingly engaging, and a lot of otherwise complex topics can be better understood this way.

Case in point: how do stars work? How are they born, live out their lives, and die? The overall story isn’t conceptually difficult, but there are some important details (like how massive the star is) and it can be easy to lose the thread. But if you watch this video, Life of a Star, your understanding will be a whole lot better:

This gives you a pretty good overview of how things work, and I’d certainly recommend it for any Astronomy 101 students who want a quick review, or sciencey-type folks who just enjoy learning about the Universe. Which, admit it, is you. There’s just enough info there to make sense of stellar life cycles, and if you want details, well, there’s Google. Or my book. Either way, if you want more fun stuff about star formation, evolution, and eventual demise, you can find it – and this video is a great start.

Tip o’ the hydrogen burning shell to Tony Silva via a chain of links starting at Giovanni Picogna.


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CATEGORIZED UNDER: Astronomy, Cool stuff

Desktop Project Part 16: A dinky galaxy with a big gas problem

By Phil Plait | April 10, 2012 6:36 am

[This is another in a series of posts I’m doing to help me clear off the zillions of cool astronomy pictures I have sitting on my computer desktop. I’ve been posting one of these every day and will continue until my desktop is cleared!]

One important aspect of science is its ability to question its own tenets. Some people think that’s a weakness, but it’s a strength! A stiff tree breaks in the wind, but a flexible one survives.

There are, of course, a lot of basic things we do know pretty well. Evolution is real, the Universe is expanding and billions of years old, and so on. As we observe nature more, we learn more, and we can add to these ideas, fill in the details. Sometimes, of course, we learn something that means our models may be wrong, or need to be modified. Again, this is a strength of science: it improves our understanding. We don’t want to think something wrong is true! We need to be flexible.

Which brings us to the weird little galaxy I Zwicky 18, which is so odd-looking I thought at first this Hubble image of it was a drawing!

But no, this is real! [Click to galactinate.]

It’s an amazing shot: it’s the sum of nearly 200 separate Hubble observations of the galaxy, giving a total exposure time of 243,000 seconds: nearly three solid days!

Wow. When I worked on Hubble, many of the images I analyzed had exposure time of only a few minutes. So yeah. This is a deep image.
Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures
MORE ABOUT: gas, Hubble, I Zwicky 18, stars

To grasp a billion stars

By Phil Plait | April 4, 2012 6:00 am

There are times — rare, but they happen — when I have a difficult time describing the enormity of something. Something so big, so overwhelming, that words simply cannot suffice.

The basic story is: Using the VISTA telescope in Chile and the UKIRT telescope in Hawaii, astronomers have made an incredibly detailed map of the sky in infrared. This map will help understand our own galaxy, more distant galaxies, quasars, nebulae, and much more.

But what do I mean by "incredibly detailed"?

This is where words get hard. So hang on tight; let me show you instead.

Here’s a section of the survey they made, showing the star-forming region G305, an enormous cloud of gas about 12,000 light years away which is busily birthing tens of thousands of stars:

[Click to enstellarnate.]

Pretty, isn’t it? There are about 10,000 stars in this image, and you can see the gas and dust that’s forming new stars even as you look.

But it’s the scale of this image that’s so amazing. It’s only a tiny, tiny part of this new survey. How tiny? Well, it came from this image (the area of the first image is outlined in the white square):

Again, click to embiggen — it’ll blow your socks off. But we’re not done! That image is a subsection of this one:

… which itself is a subsection of this image:

Sure, I’ll admit that last one doesn’t look like much, squished down into a width of a few hundred pixels here for the blog. So go ahead, click on it. I dare you. If you do, you’ll get a roughly 20,000 x 2000 pixel picture of the sky, a mosaic made from thousands of individual images… and even that is grossly reduced from the original survey.

How big is the raw data from the survey? Why, it only has 150 billion pixels aiieeee aiieeeeee AIIEEEEE!!!

And this would be where I find myself lacking in adjectives. Titanic? Massive? Ginormous? These all fail utterly when trying to describe a one hundred fifty thousand megapixel picture of the sky.

Yegads.

And again, why worry over words when I can show you? The astronomers involved helpfully made the original data — all 150 billion pixels of it — into a pan-and-zoomable image where you can zoom in, and in, and in. It’s hypnotizing, like watching "Inception", but made of stars.

And made of stars it is: there are over a billion stars in the original image! A billion. With a B. It’s one of the most comprehensive surveys of the sky ever made, and yet it still only scratches the surface. This survey only covers the part of the sky where the Milky Way galaxy itself is thickest — in the bottom image above you can see the edge-on disk of our galaxy plainly stretching across the entire shot — and that’s only a fraction of the entire sky.

Think on this: there are a billion stars in that image alone, but that’s less than 1% of the total number of stars in our galaxy! As deep and broad as this amazing picture is, it’s a tiny slice of our local Universe.

And once again, we’ve reached the point where I’m out of words. Our puny brains, evolved to count the number of our fingers and toes, to grasp only what’s within reach, to picture only what we can immediately see — balk at these images.

But… we took them. Human beings looked up and wondered, looked around and observed, looked out and discovered. In our quest to seek ever more knowledge, we built the tools needed to make these pictures: the telescopes, the detectors, the computers. And all along, the power behind that magnificent work was our squishy pink brains.

A billion stars in one shot, thanks to a fleshy mass of collected neurons weighing a kilogram or so. The Universe is amazing, but so are we.

Images credit: Mike Read (WFAU), UKIDSS/GPS and VVV


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MORE ABOUT: Milky Way, stars, UKIRT, VISTA

Bad Astronomy review: Terra Nova

By Phil Plait | October 17, 2011 6:30 am

So I finally watched the pilot episodes of the new Fox scifi drama "Terra Nova" (it airs Mondays at 8:00 p.m. ET). I found it watchable, with some potential, and like every other TV show in existence (except "Firefly") it had some things I liked and some I didn’t. I got email about it due to a couple of lines in the pilot, which I’ll get to in a sec. First, a quick overview.


Gotta get back in time

The idea behind the show (no real spoilers here, since this is all explained in the first minute of the program) is that by the year 2149, the Earth is dying. Pollution, global warming, and so on have made the planet nearly uninhabitable. People need rebreathers just to go outside, and many scenes show huge chimneys pumping smoke into the air just to hammer home that point. Population control is mandatory; having more than two kids is an invitation for the police to come.

The show centers on a family – cop father, brilliant doctor mother, rebellious teenage son, science whiz-kid teenage daughter, and their youngest, a girl. And yeah, if you count three kids, good for you! That drives part of the plot in Part 1 of the show, so I won’t spoil it.

The big plot device in the show is that a fracture in time is discovered — how and why are not disclosed, perhaps to be revealed in a later episode — that goes to 85 million years in the past. People are being sent back in time to populate the still-clean planet, save humanity, fight dinosaurs, and so on.

I’ll note that I like how the time travel was handled. When we join the story, time travel has already been around a while — this family is sent back as part of the tenth wave of colonists — so the writers didn’t have to spend a lot of time talking about how it was done. It just is. Also, the writers circumvented the inevitable fan rage with a short expository scene stating how this isn’t really our past; the time line has split, so it doesn’t matter if you step on a butterfly or eat an entire herd of dinosaurs. It won’t change the future. That made me smile. Score one (pre-emptively) for the writers.

Of course, the show tried to distance itself from "Jurassic Park", and did so by having the first look at the dinosaurs be a herd of brachiosaurs, and then having the main characters in souped-up jeeps getting chased by a carnivorous velociraptor/T-Rex-like animal.

Um, yeah. Oops.

I’m no paleontologist, and I like watching dinosaurs with big sharp teeth eat a person as much as the next guy, so that part was fine. But then they went a little bit out of their way to add some astronomy, and kinda blew it. So I have to jump in here a bit.

What follows is me nitpicking the science of a couple of lines of dialogue. I don’t do this to be petty — I gave up on that in my reviews a long time ago — but just to use these lines to point out the real science. Any snarking is incidental.

Read More

Successful stars talk dead stars

By Phil Plait | October 16, 2011 7:36 am

I somehow missed it when it came out, but the folks at IRrelevant Astronomy have a great video about how stars die, and it has Sean Astin (Samwise!) and Sandeep Parikh (Zaboo!).

IRrelevant Astronomy is a very funny web series about infrared astronomy put together by folks at Spitzer Space Telescope, and they’re all pretty good. This one is a followup for <a href="http://blogs.discovermagazine.com/badastronomy/2009/10/26/felicia-day-collides-galaxies/" target="_blank"a great video about galaxies featuring Felicia Day. They also have a couple with a guy named Wil Wheaton. Never heard of him myself, but he has promise as an actor, I think.

If you have the time, you should watch ‘em all. They’re funny, and well done, and you just might learn something.

Tip o’ the beryllium mirror to Jennifer Ouellette on Google+.


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CATEGORIZED UNDER: Astronomy, Cool stuff, Humor

Charlie talks stars

By Phil Plait | October 12, 2011 7:00 am

Charlie McDonnell is an adorable young man who has an amazingly popular video series he does on YouTube. His latest is a quick primer on stars, and why they’re awesome:

I have to say, that’s pretty good! Accurate, fast, fun, and adorable. Did I already say "adorable"? Well, he is.

He has other videos in his Fun Science, like ones on sound, light, and the Moon. I can easily see these being shown in classrooms; kids will like ‘em, and if they like something, they’re more likely to let it sink in.

And that’s the point.

Tip o’ the lens cap to Ali Marie via Fraser Cain.

CATEGORIZED UNDER: Cool stuff, Science

Supernovae popping off like firecrackers in Carina

By Phil Plait | May 24, 2011 10:47 am

The Carina nebula is a sprawling, monstrous complex of gas located a mere 7500 light years from Earth. Hundreds of light years across, it’s massive enough to create thousands of stars like the Sun. Tens of thousands.

And churn out stars it does. Embedded in the nebula are several clusters of newborn stars, and many of these stars are so massive they’re nearly at the limit of how big a star can be without tearing itself apart. Stars that big explode as supernovae, and a new mosaic by the orbiting Chandra X-ray Observatory indicate they’ve been popping off in the nebula for quite some time:

[Click to enchandrasekharlimitenate.]

This image is pretty amazing: it’s a mosaic of 22 separate images by Chandra, covering 1.4 square degrees (seven times the area of the full Moon on the sky), and represents an exposure time of 1.2 million seconds! Since it shows X-rays coming from astronomical objects, it’s false color: red is from lower energy X-rays, green is medium energy, and blue from the highest energy photons.

The diffuse glow is from two sources: the stellar winds from those massive stars slamming into surrounding ambient gas at high speed, and from the shock waves generated when supernovae explode. Both are extremely high-energy events, and produce copious amounts of X-rays. That long, horizontal arc is probably the edge of a bubble, a shell of gas piled up from the winds of stars and supernovae like snow piled up in front of a snowplow.

That’s evidence right there that Carina has been cranking out supernovae over the past few million years. Interestingly, it’s what’s missing that provides more proof. Read More

A vast, cosmic cloudy brain looms in a nearby galaxy

By Phil Plait | June 22, 2010 10:50 am

Deep inside the Milky Way’s companion galaxy called the Large Magellanic Cloud lies a vast complex of stars, gas, and dust. From our vantage point, 170,000 light years away, we see it as a softly-glowing pinkish brain-shaped cloud studded with stars — a description that grossly underdescribes the tremendous beauty of the newly-released Hubble view of it:

hst_n11

Oh, my. Click it to get a bigger version, or go here to get a 26 Mb 4000×4000 pixel version.

hst_n11_bluestarsWhat a staggeringly lovely image! And so much to see. More than you’d expect… but that’s part of a surprise I’ll have for you at the end of this post. Bear with me, it’s worth it.

Until then, let me show you a thing or two…
Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures

Time spent doing what you love is never wasted

By Phil Plait | June 17, 2010 10:00 am

Recently, I was performing the mundane task of taking out the trash.

I went from room to room, collecting the detritus of the week. I then spent a few minutes scooping out and changing the cat litter, and, sighing, finally tied up the bag and hauled it out to the bins around the side of the house.

As I lugged the hefty bin out to the curb in the darkness, I did what I do, what I always do, when I go outside: I looked up.

I was greeted instantly with an astonishing sight: the reddish, glowing dot of Mars bumped right up against Regulus, the brightest star in Leo. The two were paired less than a degree between each other, low over the western horizon.

It was beautiful. Mars was the slightly brighter of the pair, and even in the mildly light-polluted and sparsely clouded night sky of Boulder I could see the color difference between the planet, some 240 million kilometers away, and the star, 3 million times farther distant yet.

I let my gaze drift a bit over and saw Saturn looming near Leo’s other end. Venus, I knew, was already behind the mountains, but I could see the Big Dipper standing on its bowl to the northwest. Following the arc of the dipper’s handle, I was led to mighty Arcturus, an orange giant nearing the end of its life, and a harbinger of things to come for our own star. Turning, was that Vega I saw dancing in between my neighbor’s tree branches? Why yes, yes it was. Summer’s coming, Vega is telling me.

My trash-hauling chore was forgotten. I suddenly had a flashback, visceral and total, of being a teenager. Standing at the end of my family’s driveway, I watched the sky. Every clear night you’d find me out there. I spent hundreds of hours, thousands, either gazing with my eye to the telescope or simply with my chin tipped up, the Universe unfolded above me. I would always have to pause when a car drove by, and while my absorption with the task didn’t allow it to occur to me then, I now wonder how many of those people saw me and thought to themselves that I was wasting my time.

But as I stand outside my house as an adult, gaping up at the sky, I am familiar there. The stars are my friends… no, that’s hopelessly anthropomorphic and somewhat twee. But they are like slipping your feet into well-worn slippers, like the first bite of a recipe you’ve perfected by countless trial-and-error meals, like holding a book whose spine has been softened through years of reading and re-reading.

I’m comfortable with the sky. I’m at home there. When I stand in my yard and look up, my heart sings and my mind reaches out. My weekly chore was interrupted, delayed, but it didn’t matter.

I don’t know what your own passion is. But I will say this, and you hear me well: no time is wasted spent under the stars. And no time is wasted spent doing what you love.

Picture credit: Il conte di Luna’s Flickr photostream, used under the Creative Commons license.

CATEGORIZED UNDER: Astronomy, Piece of mind

A thousand trillion suns

By Phil Plait | May 5, 2010 12:30 pm

What does it look like to stare into infinity? Like this:

eso_abell315

Oh yes, you need to click that to see it in its glory. Because there’s a lesson here…
Read More

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